Despite the number of substances that fall under the rubric of solvent, only a few are considered to be potential carcinogens. The purpose of this article is to provide readers with an overview of the cancer data that exist for a number of solvents currently in commercial use. These solvents include chloroform, carbon tetrachloride, methylene chloride (dichloromethane) trichloroethylene, tetrachloroethylene (perchloroethylene), and 1,4-dioxane. Although benzene also would be considered a solvent, the data concerning its carcinogenic potential are presented in another article in this issue and are not discussed in this article.